Lapping machine



March 4, 1958 K. L. LINDQUIST LAPPING MACHINE 5 Sheets- Sheet 1 Filed July 13, 1955 INVENTOR llE/V/VE TH L. LINDQU/ST A TTOE VEY K. L. LINDQUIST LAPPING MACHINE March 4, 195 2,8

Filed July 13, 1955 3 Sheets-Sh eat 3 NZ! UZZ kF/VNE Th L. L

IN V E NTO R. //vp0u/sr ATTORNEY United States Patent tio'rnpany, Worcester, Mass., arcorporation of Massachusetts- Application July 13, 1955,'-Serial No. 521,804

2 Qlaims. (Cl. 51131),

The invention relates to lapping machines. and more particularly to a single wheel lapping machine for. lappingna'plane surface on a plurality, of work pieces;

One. objects of the invention is to provide a simple and thoroughly practicalla'pping machine. Another objectis to provide a single wheellappingmachine havinga plane operative faced lap for simultaneously lapping, a plurality of pl-ane-faced work pieces. v Another object is to provide a lapping machine in: which the, work'carry ing cagemay' be separated from the" lap bymeans of'a hydraulically operated mechanism. Another object of the invention is to -provide apressure actuated mechanism for applying pressure independently to each of the work pieces to produce the desired lapping action; Another object of the invention is to provide a fluid pressure operated; mechanism for supplying pressure independently to each workpiece during a lapping operation which is automatically moved to an inoperative position t'of-acilitatedoadihg work pieces into the-machine when a finish lapped war-k piece has moved to a loading station; Other objectst-will be in part obvious or in-part pointed'outhe'r'einafter. v

In theza'cc'ompan ying drawings, in which" is: shown one of. various possible embodiments ofthe" mechanical-fewtures of: this invention,

Fig. 1- is 'afrontelevation of theflapping'machinehavingrnparts broken awayand shown in section, I-iigx2 is aplanview of the lappingmachine;

Fig. 3 is a hydraulic diagram showing the hydraulic-liftfor: the workvcagej Fig. 4'is a fragmentary' vertical sectional view through the; rotary con-trol? valve :for controlling the workxpres sure devices; and! 'Fig. 5: is a fragmentary sectional: view,fon an'enlarged scale:-takeniapproximatelyon theline 5-5 of Fig. 4,

havingzparts of; the. rotary controlvalvebroken away, combined with a piping diagram: showing 'th'e. air pressure system for: supplying lapping pressure;

Allapping. machine has been; illustrated in the drawings comprising: arbase ltl which supports a'r elatively largediameter plane-faced lapping wheel- 11. The lapping' wheeli11- is mounted on aplate 1 2' which is in turn fixedly mountedron a'spider 13: The-spider l3 is keyedonto the upper'endiof. a: vertically arranged rotatable shaftil tilwhictn is: journalled in space'd bearings" '15 and lousupported bythe base ll tla The lapping whe'e1 11- isprovided? with a; plane operativeface' 1 7 for lapping a singlerplane: faceion at pluralitylof work. pieces;

driving mechanism. is provided for imparting a re;- tangmotion to' th'e lappingiwheelfil l comprising an electr-icz motort 20' which: is adjustablyi mounted on a projectingportion' oilthe base The motor ZOis -Provide'd' withzazmotorrshaftil having a-sprocket 22 which iscon' nectedrbyia' link chain 23'-wi-th a s'pro'ck'et 24.- The sprock-- et. 24% is; fixedly:- mounted on aLrotataEIeL shaft: 25 which is journalledini separate: bearings 26 'andt 27' fixedly mounted onrthe, basexllh: ThflShHffiZSlS provided with aspr'ocket 28swhichiis connected: byte-link chain 29".witlr aisprocket 2,825,187 PatentedtMar. 4, 1958 30 mounted' on'a rotatable shaft .31. Thelshaft 31::is journalled in a plurality of spaced bearings 32,, 33 and 34 which are fixedly mounted relativeto the base 10.. The shaft 31 is provided with a worm 35 which, meshes:

wi-th'a worm gear 36 which is fixedly mountedwonthevlower,

column 40 which supports a vertically arranged shaftv 41. The shaft 41 supports the right hand end of across arm 42. Due to the size of the machine, itis desirable to provide a support for the outer end of the arm 42 by means of an extension 42a3to prevent deflection thereofi during a lapping operation. The right hand end of the,

arm extension 42a is fixedly mounted on the leftvhand end of the arm 42. A vertically arranged shaft or red 43 is supported at its lower end by a bracket 44"fixedlymounted on the base 10. Theupper end of the shaft 41 is provided with a threaded portion 45 which passes through a clearance hole 46 at the cross arm extension 42a.

A pair of nuts 47'and 43'a're threaded onto the portion 45 and serve to verticallyadjust the left hand end" of the cross arm extension 42a and to lock'the same in ad-' justed position.

The cross arm 42 serves as a support for a vertically movable plate 59. The-plate '50 is keyed onto thelower end of a vertically arranged spindle 51 which is in turn rotatably supported within a sleeve or quill 52. The, quill 52 is provided with a pair of spaced bearings'53 and 54-for rotatably supporting the spindle 51. The quill 52 is slidably keyed within a cylindrical aperture 49 formed in the cross arm 42' so that itmay be movedin a vertical direction relative thereto. The plate'50 serves as a driving mechanism for a work cage to be hereinafter described and also as asupport for pressure-devices; for applying pressure to the work piece during a lapping operation.

A driving mechanism is provided for the plate 50 comprising a motor 55 Which is formed as-an integral part of a variable speed driving'unit 56, such as for example, a Graham integral motor variable speed transmission. The variable speed unit drives a pulley '57 which is serrated on its periphery to drive a cog belt 58, such as a Gilmer tiiningbelt. The timing belt 58 drives a'pulley 59 which is'formed integral with. a rotatable sleeve 6t}. 60 is rotatably journalled in spaced anti-friction bearing's 61, only one of which has been illustrated, which are carried by the arm 42. The upper end on spindle 51 is slidably keyed within a central aperture in the sleeve 60 so that when the motor 55 is started a rotary motion will be imparted-through the mechanism above described collar 72 is threaded onto a threaded portion 73 on thesleeve 52. The collar 72' is arranged to engage a stopv surface'74 formed integral with the-arm 42 so as-to limit the downward movement of the sleeve and the partsassociated'therewith.

The-plate 59 is provided with a plurality of'adjustably' positioned studs 65, 66',- 67 and68the lower ends-of-which' I arev connected'to thework'cagew. When the plate 50.-is-" in a downward' or operative position, the studs fi5g 66, 67

It will be readilyfapparent- The sleeve 3 and 68 may be adjusted so as to position the work cage 69 relative to the lapping wheel 11. The studs 65, 66, 67, and 68 serve also to impart a rotary motion to the work cage 69. The work cage 69 is provided with a plurality of spaced work receiving apertures 70, 7%, 76."), 70c, 70d, 79a, 76; and 70g for positioning work pieces 71, 71a, 71b, 71c, 71d, 71c, 71 and 71g to be lapped. The motor 55 and the variable speed unit 56 serve to imuart a slow rotary motion to the plate 59 and the work cage 69 at speeds ranging from zero to 3 R. P. M. de .nding upon the lapping operation to be performed. 11:; l lnstratcti in the drawings eight work receiving apertures are provided. For different types and sizes of work, the number and size of cage apertures may be varied, that is, if smaller work pieces are to be lapped smaller sized apertures are re quircd and, therefore, more apertures may be provided in the cage 6).

The axis of the spindle 51 is offset relative to the axis of the spindle 14 (Fig. 2) so that as the work pieces are revolved on the operative face 17 of the lapping wheel 11, they travel from the outer periphery of the lapping surface to the inner surface and then again to the outer surface thereby equalizing the lapping action and producing an even wearing of the lapping wheel due to the lapping operation.

It is desirable to provide a suitable power. operated lifting mechanism to raise and lower the plate 50 together with the spindle 51 and the work cage 6? to and from an operative position. This mechanism is preferably a fluid pressure operated mechanism comprising a pair of diametrically opposed fluid pressure cylinders 75 and 76 which are arranged on diametrically opposite sides of the spindle 51 so as to equalize the pressure exerted upon the plate 50. The cylinders 75 and 76 are supported in fixed position relative to the cross arm 42. The cylinders 75' and 76 contain slidably mounted pistons 77 and 78 which are connected to the lower ends of a pair of piston rods 79 and 80 respectively. The upper ends of the piston rods 79 and 80 are fixedly connected to a flange plate 81 carried by the upper end of the sleeve or quill 52.

A fluid pressure system is provided for supplying fluid under pressure for the lift mechanism comprising a motor driven fluid pump 32 which draws fluid through a pipe 83 from a fluid reservoir 84 and forces fluid under pressure through a pipe 85. An adjustable pressure relief valve $6 is provided in the pipe line 85 to facilitate passing excess fluid under pressure directly to the reservoir 84. By adjustment of the relief valve 66. the desired operating pressure may be maintained within the fluid system.

A manually operable control valve 37 is provided for controlling the admission to and exhaust of fiuid from the cylinders 75 and 76. The control valve 37 is preferabl a piston type valve having a valve stem 88 formed with a plurality of spaced integral valve pistons which forma pair of spaced valve chambers 539 and 90.

In the position of the valve 87 (Fig. 3) fluid under pressure passing through the pipe 85 passes through a valve chamber 93, through a pipe 91 into a pair of cylinder chambers .72 and 93 formed in the upper ends of cylinders 75 and 76 respectively. Fluid under pressure entering the valve chambers '2 and 93 serves to cause a. downward movement of: the pistons 77 and??? to move the quill 52 together with the spindle 51 and the plate 59 and the work carrying cage 69 downwardly into an operative position. During the downward movement of the pistons 77 and 7 8, fluid within cylinder chambers 94 and 95 exhausts through a. pipe 96, through the valve chamber 89 and through an exhaust pipe 97 into the reservoir 84.

A manually operable mechanism is provided for actuating the control valve 87 comprising a manually operable lever 98 which is mounted on a rock shaft 99 carried by the cross arm 21. A short arm 166 is also fixedly mounted on the. rec; shaft 99. The left hand end of the arm 1% is connected by a stud 191 with the valve stem 88. When it isdesired to move the plate 56 and the work cage 65 upwardly to an inoperative position, the control lever 98 is rocked in a clockwise direction to shift the valve stem 88 upwardly (Fig. 3) so that fluid under pressure from the pipe 35 passes through the valve chamber and through the pipe 96 into the cylinder chambers 94 and to cause an upward movement of the pistons 77 and 78 so as to move the quill 52 together with the spindle 5i and the plate 59 upwardly into an inoperative position. During the upward movement of the pistons '77 and 78, fluid within the cylinder chambers 92 and 93 respectively exhausts through the pipe 91, through the valve chamber 90 and through the pipe 97 into the reservoir 8 It will be apparent from the foregoing disclosure that by manipulation of the control lever 98 the plate 55} may be raised and lowered as desired.

in order to obtain the desired lapping pressure of the work piece 71 upon the operative face of the lapping wheel 17, a plurality of independent air or fluid pressure operated mechanisms are provided, one for each work aperture in the work cage 69. As illustrated in the drawings a plurality of air cylinders 110, a, 110b, 1100, 1100!, 110e, 1101 and 110g are provided which are fixedly mounted on the plate 50. These cylinders are arranged with their axes aligned with the centers of the work receiving apertures 70 in the cage 69. The cylinders 110, 110a, 110b, 1100, 110d, 110e, 1101 and 110g are each provided with a piston 111, 111a, 111b, 111e, 111d, 111e, 111) and 111g respectively which are fastened to the upper end of piston rods 112, 112a, 112b, 112e, 112d, 1122, 112 and 112g respectively. Plates 113b, 1130, 1132, and 113, are fixedly mounted at the lower end of each of the piston rods. Each of the plates 113b, 1130, 1132, and 113) are yieldably connected by a plurality of studs with work engaging plates 116b, 1160, 116e, and 116 respectively which are arranged to engage the upper surface of the work pieces 71b, 71c, 71e and 71). Compression springs b, 1150, 1152, and 115 surround the studs 114 and are interposed between the plates 113b, 1130, 1132, and 113 and work engaging plates 116b, 1160, 116e and 116 so that when the pistons are moved downwardly to move the work engaging plates 116b, 116e, 116e and 116i into operative engagement with the work pieces 71b, 71c, 71c and 71), the springs 115b, 1150, 115e, and 115; compress to yieldingly maintain the plates 116b, 1160, 1162 and 116f in engagement with the work pieces during a lapping operation.

In order to facilitate semi-automatic operation of the machine, the work engaging plates 116b, 1160, 116d, 116e and 116 together with the associated parts are arranged so that as they approach a loading position, the pistons. are raised automatically to lift the plates 116b, 1160, 116d, 116a and 116 vertically to facilitate removal of the finish lapped work piece and the insertion of a new work piece thereinstead.

The automatic actuation of the work engaging plates is preferably controlled by a rotary valve which is operatively connected to automatically control the admission to and exhaust of air or fluid from the cylinders 110, 110a, 110b, 110e, 110d, 110e, 110f and 110g. The rotary valve 120. comprises an upper stationary valve member 121 which is fixedly mounted on the lower end of the quill or sleeve 52. A lower member 122 of the valve 120 is keyed to the spindle 51 and rotates therewith. A disc 119 of a resinoid material such as Formica impregnated with molysulfide is fixedly mounted on the upper surface of the member 122 of the valve 120 and serves to provide a bearing surface between the upper stationary valve member 121 and the lower rotary member 122 of the valve 120. In order to adjust the pressure between the valve members 122 and 121 of the valve 120, a plurality of compression springs 123 are provided, each of which is supported by a stud 124. The studs 124 slide within holes 125 formed in the lower member 122 of the valve 120. The heads of the studs 124 bear against the upper surfaceof a collar 126 which is screw threaded pressure-between'the'valve'members 122' and12-li.

The lower surface" of the upper" member 121 of thevalve 120" is provided with a plurality of arcuate-shaped grooves or-valve chambers comprisinga-pressure chamber130; an exhaustchamberfil," apressurechamberj132 andanexhaust' chamber 133i Thepressurechamber 132 and exhaust chamber 133 serve to control the flow of air under pressure to the cylinders as they pass through an unloading station automatic-ally to raise'the pistons 111, 1 1 1 114 ..,1 .lllL a lllgfiheleby a the q l fl l l llales lfibts fi ..1- and:116f from the workpieces Z1 to/faeilitate removal'of alappedqpiecerof work andthe insertion of a newpiece of work to be lapped thereinstead. The pressure chamber 130 and exhaust chamber 131 serve to control the flow of air under pressure to the cylinders 110 to maintain a predetermined pressure between the work being lapped and the lapping wheel 11 during the lapping cycle. Fluid under pressure, such as, air under pressure or fluid under pressure may be utilized for actuating the pistons 111, 111a, 111b, 1110, 111d, 111e, 111 and 111g. As illustrated in the drawings air under pressure may be supplied from any suitable source through a pipe 135 which conveys pressure to the pressure chambers 130 and 132 of the valve member 121. An exhaust pipe 136 is connected to allow air to exhaust from exhaust chambers 131 and 133. A pressure regulating valve 137 is provided to facilitate regulating the air under pressure passing from the pipe 135 into the pressure chambers 130 and 132. It will be readily apparent from the foregoing that by manipulation of the pressure regulating valve 137, the pressure of the work pieces 71 against the operative face 17 of the lapping wheel 11 may be readily varied as desired to obtain a predetermined lapping action.

As above described the cylinders 110, 110a, 110b, 110a, 110d, 110e, 110 and 110g are fixedly mounted on the plate 50 which is rotated by the spindle 51 together with the work cage 69. A plurality of pipes 146,146a, 146b, 146e, 146d, 146e, 146 and 146g are connected between the lower ends of the cylinders 110, 110a, 110b, 110e, 110d, 110e, 110 and 110g respectively and the rotary valve 120. A plurality of pipes 147, 147a, 147b, 147e, 147a, 147e, 1471, and 147g are connected between the upper ends of the cylinders 110, 110a, 110b, 1100, 110d, 1102, 110 and 110g respectively and the rotary valve 120. As the cylinders 110, 110a, 110b, 1100, and 110d, 1102, HM and 110g approach the position 110 (Figs. 2 and 3), as soon as the port 145 at the end of the pipe 146 is uncovered due to the rotary motion of the lower valve member 122 air or fluid is passed through the pipe 146 into the lower end of cylinder 110 to raise the piston 111 thereby moving one of the plates together with one of the work engaging plates upwardly to an inoperative position so that the lapped work piece 71 may be removed from the cage 69 and replaced with a new work piece to be lapped. Fluid within the upper end of the cylinder 110 may exhaust through the pipe 147 into the exhaust chamber 133 and out through the exhaust pipe 136.

As the work cage 69 together with the plate 50 rotate in a counter-clockwise direction so that cylinder 110 approaches the position of 110a, the flow of fluid under pressure to the cylinder 110 is reversed so that the piston 111 moves downwardly to position one of the work engaging plates in operative engagement with the work piece to be lapped at the desired pressure. The work piece remains under the desired lapping pressure until the cylinder 110 moves through the position 110g illustrated in Fig. 3 at which time the work piece has been lapped to the desired extent and the parts are raised to facil- 6 itate a -loading operation. Asillustrate'd 'in the drawings eight cage apertures -70 arei-t'provided in the cage 69 that while': one wonky-piece islpa'ssing through theloading and unloading stationsseven:otherrwork-pieces. arezin the process of beingzlapp ed; The:numberofeworkpieces that'mayrbe lapped :simultaneously; depends upon the size and; shape of: the: work .piece::.which determines the nurnber; of: cage apertures andz pressure: devices-.whichnmay be provided; In.- any; case: theresis a cylinder 110,: and; the associate parts located. directly above each? cage-- aperture 70. V

g The operation-of the improved: lapping-machine will-be: readily, apparent from:- theg-foregoing. disclosure. Assuming; all of. the mechanismsr to; have "been previously adjusted, the' rnotor 20,i s;- started.to5impart ai-rotarymotiom to-the lappingwheeltllt. Themotor 55 .-is'starte d=to;ime parta; rotarymotiontto the platetSdand the work cage;- 69. The fluid pump 82 is then started after which the control lever 98 is moved in a counter-clockwise direction to move the valve stem 88 downwardly into the position illustrated in Fig. 5 thereby causing a downward movement of the spindle 51, the sleeve 52, the plate 50 together with the work cage 69. The downward movement continues until the stop collar 72 engages the stop surface 74 so as to position the work cage 69 in an operative position. Air under pressure is then supplied to the pipe 135 to control the actuation of the pistons 111. A Work piece 71 is then positioned in the cage aperture 70. As the cage 69 rotates in a counter-clockwise direction, after the ports to the cylinder are cut off from the valve chambers 132 and 133 and opened to the chambers and 131, the passage of air under pressure to the cylinder 110 is reversed to cause a downward movement of one of the work engaging plates into operative engagement with the upper surface of the work piece 71 Where it remains during the entire lapping operation.

As successive cage apertures approach the unloading and loading position, the same cycle of events takes place. A lapped work piece 71 is removed from the cage aperture and a new work piece inserted thereinstead during the time the cage aperture passes through the unloading station. being lapped takes place while the ports for the cylinder 110 are in communication with the pressure chamber 130 and the exhaust chamber 131. The unloading operation and loading operation take place While the ports from any of the cylinders 110, 110a, 110b, 110e, 110d, 110e, 110 and 110g are in communication with the pressure chamber 132 and the exhaust chamber 133.

It will thus be seen that there has been provided by this invention apparatus in which the various objects hereinabove set forth together with many thoroughly practical advantages are successfully achieved. As many possible embodiments may be made of the above invention and as many changes might be made in the embodiment above'set forth, it is to be understood that matter hereinbefore set forth or shown in theaccompanying drawings is to be interpreted as illustrative and not in a limiting sense.

I claim:

1. In a lapping machine having a base, a rotatable plane-faced lapping wheel thereon, means to rotate said lapping wheel at a predetermined speed, a rotatable platen, a rotatable work carrying cage supported by said platen which is arranged to rotate about an axis oifset relative to the axis of said wheel, means including a variable speed driving mechanism for rotating said platen and cage at a predetermined speed to facilitate varying the lapping action, a plurality of spaced work receiving apertures in said cage, means to move said platen and cage vertically to and from an operative position, a positive stop to determine the operative position of said cage, means including an independent pressure cylinder and piston on said platen aligned with each cage aperture for maintaining the desired lapping pressure of the work against the said The entire lapping operation on the work piece lapping wheel, means including a valve to regulate said pressure to facilitate varying the pressure of the work against the face of the lapping wheel, and means including a rotary control valve to control the admission to and exhaust of fluid from said cylinders.

2. In a lapping machine having a base, a rotatable plane-faced lapping Wheel thereon, means to rotate said lapping wheel at a predetermined speed, a vertically movable rotatable platen on said base, a work carrying cage adjustably supported by said platen with its axis offset relative to the axis of the lapping wheel, means including a variable speed driving mechanism for rotating said platen and said cage at a predetermined speed, a plurality of spaced work receiving apertures in said cage, means to move said platen and cage vertically to and from an operative position, a positive stop to determine the operative position of said platen and cage, means including an independent pressure cylinder and piston mounted on said platen aligned with each cage aperture for maintaining a predetermined lapping pressure of the work piece against said lapping wheel, means including a pressure regulating valve to vary said lapping pressure, and means including a rotary control valve to control the admission to and exhaust of fluid from said cylinders, said "rotary control valve serving to reverse the flow of pressure to said cylinders during movement through a loading station to facilitate a work loading operation.

References Cited in the file of this patent UNITED STATES PATENTS 387,482 Ball Aug. 7, 1888 1,832,190 Doane Nov. 17, 1931 1,921,715 Whitney et a1 Aug. 8, 1933 2,695,479 Indge Nov. 30, 1954 

